using Embedded Resources widget component

Hi,
I am trying to display a video from external resource. for that I am using the browserframe example code given in vaadin website.
code I am using:

[b] BrowserFrame browser = new BrowserFrame("Browser", new ExternalResource("http://demo.vaadin.com/sampler/")); browser.setWidth("600px"); browser.setHeight("400px"); layout.addComponent(browser); [/b] I am able to access the url mentioned and able to get the video played in chrome and firefox. when trying the same in internet explorer9 and safari I am getting error.
Here is the error I am getting:
[color=#FF0000]
HTTP Status 500 - com.vaadin.server.ServiceException: java.lang.NullPointerException
type Exception report

message com.vaadin.server.ServiceException: java.lang.NullPointerException

description The server encountered an internal error that prevented it from fulfilling this request.

exceptionjavax.servlet.ServletException: com.vaadin.server.ServiceException: java.lang.NullPointerException com.vaadin.server.VaadinServlet.service(VaadinServlet.java:239) javax.servlet.http.HttpServlet.service(HttpServlet.java:728)root causecom.vaadin.server.ServiceException: java.lang.NullPointerException com.vaadin.server.VaadinService.handleExceptionDuringRequest(VaadinService.java:1463) com.vaadin.server.VaadinService.handleRequest(VaadinService.java:1417) com.vaadin.server.VaadinServlet.service(VaadinServlet.java:237) javax.servlet.http.HttpServlet.service(HttpServlet.java:728)root causejava.lang.NullPointerException com.vaadin.demo.sampler.component.GuideWindow.open(GuideWindow.java:202) com.vaadin.demo.sampler.SamplerUI.init(SamplerUI.java:99) com.vaadin.ui.UI.doInit(UI.java:641) com.vaadin.server.communication.UIInitHandler.getBrowserDetailsUI(UIInitHandler.java:222) com.vaadin.server.communication.UIInitHandler.synchronizedHandleRequest(UIInitHandler.java:74) com.vaadin.server.SynchronizedRequestHandler.handleRequest(SynchronizedRequestHandler.java:41) com.vaadin.server.VaadinService.handleRequest(VaadinService.java:1405) com.vaadin.server.VaadinServlet.service(VaadinServlet.java:237) javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
[/color]

can anyone help me in solving this issue.